Volunteer assemble a Kalashnikov before shooting practice in their camp organised by the Eurasian Youth Union

The militias are thought to come from the ultra-nationalist Eurasian Youth Union who detest the western powers such as the US and Britain.

Putin expert and biographer Boris Reitschuster asserts in his new book "Putin's Hidden War" that secret reports detail the formation of covert fighter groups across the continent including France and Germany.

"This means the Kremlin leader and ex-Intelligence chief Putin has direct access to an elite fighter network in the West," he told Bilde, a German tabloid newspaper.